Emergency actuating system for fluid motors



1944- v H. E. HEIGIS 2,365,700

EMERGENCY ACTUATING SYSTEM FOR FLUID MOTORS Filed May 8, 1941 2 Sheets-Sheet 1 VBY ATTORN Dec. 26, 1944. l s 2,365,700

EMERGENCX ACTUATING SYSTEM FOR FLUID IOTORS- Filed-May 8, 1941 2 Sheets-Sheet 2 INVENTOR' I BY J N $3 A'ITORN Patented so. 26

EMERGENCY ACTUATING SYSTEM FOR FLUID MOTORS Henry Ernest Heigis, West Orange, N. 5., assignor to Specialties Development Corporation, Bloomfield, N. .33., a corporation of New Jersey Application May 8, 1941, Serial No. 392,447

6 @iaims. The present invention relates to fluid pressure controlled apparatus; and more particularly to fluid pressure controlled apparatus for eiiecting normal and emergency. operation of accessory gear or devices of aircraft and the like, and to a method of operating such apparatus.

Airplanes and seaplanes usually are provided with one or more accessory devices, mechanisms, or gear, ior accomplishing operations which are incidental to the flight ofthe plane. For example, airplanes may be provided with retractible and extensible landing gear. Bombing planes may be provided with mechanism for opening bomb bay doors prior to releasing the bombs or other explosive charges. and for closing the doors after dropping the bombs or charges. Other types of planes, such as transport planes, may be provided with mechanism for opening. and closins doors or hatches from which the passengers of the plane may parachute or through which the cargo of the plane maybe dumped. Such mechanisms preferably are operated by liquid pressure meters or hydraulic pressure actuated apparatus; for example, omprising a cylinder, 9. piston in-the cylinder actuated by a hydraulic pressure medium, and suitable means for operatively connecting the piston to the landing gear or doors. Usually, the hydraulic pressure medium employed is an oil of the mineral oil type which is compressed by a compressor system to exert a pressure of about 950 pounds per square inch.

The dimculty with hydraulic apparatus of the foregoing type is that it operates the doors, landing gears or the like, rather slowlyand in an emergency does not havethe required speed and power to effect almost instantaneous operation. Frequently, bombing planes taking of! with a load of bombs are unable to attain an altitude required to clear buildings, structures or natural obstructions at the airport, either due to engine trouble or other causes primarily due to the heavy load carried by the plane. Under such circumstances it is imperative to release the bombs in a minimum period of time to enable the plane to lighten its load in order tov gain altitude or to permit the" plane to land safely. Another contingency which frequently arises is that when a plane is preparing to land, the landing gear may be jammed in its retracted position and cannot be extended because the hydraulic apparatus lacks the power to move the landing gear. A

The present invention aims to overcome the foregoing dimculties by providing apparatus for effecting operation of doors, hatches or landing gear and the like, which under normal conditions is actuated by a hydraulic pressure medium and in an emergency is actuated by a gaseous pressure medium which may have a greater pressure than the hydraulic medium and which is reserved solely for emergency operation. The invention further contemplates discharging, preferably to the atmosphere, the hydraulic medium in the fluid motor or the cylinder, so that the gaseous medium is more effective to provide rapid and positive operation. In addition, the invention aims to relieve excessivepressure due to the gaseous medium which might damage the apparatus, and to vent the gaseous pressure medium to the atmosphere prior to or after actuation of the apparatus by the gaseous pressure medium, to prevent premature or accidentally released or trapped gaseous medium from accidentally actuating or interferingwlth the actuation of the apparatus.

similar contingency may arise in connection with other doors or hatches usedfprimarily for the escape of passengers or the dumping of cargo.

An object of the present invention is to provide an improved apparatus for operating bomb bay doors, landing gear and the like, which is simple and economical in construction, rapid and positive in operation in the event of an emergency, and which can be readily installed.

Another object is to provide control devices for apparatus of the foregoing type, which adapt the apparatus for normal hydraulic actuation and for gaseous actuation in the event of an emergency.

Another object is to provide an improved apparatus which does not materially increase the weight of the plane and comprises a minimum number of parts, fittings and connections.

Another object is to provide an improved apparatus which requires a minimum amount of servicing and repair and can readily withstand rough usage.

A further object is to provide an improved method of controlling and actuating apparatus door operating apparatus, illustrating the principal parts in section.

Referring to Figure .1 of the drawings, there is shown an airplane iii of the bomber type having The fuselage may haveone or t grammatically at l4, which actuates afluid pres-'-,

sure motor, such as an-individual cylinder and piston arrangement ii for operating each of the doors or each set of doors. The doors are adapted to be opened,-. or opened and closed if desired, 7

when an emergency arises by utilizing a source of gaseous pressure medium stored in a container It for actuating the fluid pressure motor. Suitable valves, connections, and control devices are provided, which will be described in detail in conn'ectionwith Figure 2, and operation of'the doors, either by a hydraulic medium or a gaseous medium may be controlled by suitable devices on the instrument and control panel II of the plane.

Referring to Figure 2, there is'shown in detail a cylinder IS, a door operating piston I! in the cylinder, and a piston rod secured to the piston and adapted to'be operatively connected by suitable linkage (not shown) to a bomb bay door or the like. The piston II is adapted to be moved in either direction by a liquid pressure medium supplied by the hydraulic system l4 which comprises-an oil reservoir 2|, a pump 22 for withdrawing on from the reservoir through a pipe line 24, a hydraulic accumulator 25 for receiving oil under pressure from the pump through a pipe 26, and a direction valve 21 adapted to selectively direct the oil'under pressure toeither end of the-cylinder l5 and to permit the oil at the other end of the cylinder to return to the reservoir II.

The valve 21 has a cylindrical casing 20 provided with four ports 29, 30, II and 32, spaced 90 apart, and pipes or conduits, 24, 35,16 and 31 connect the ports 20, 30, ll and 32 to the accumulator 25, to a control valve 38, to the reservoir 2|, and to a control head 40, respectively. A rotatable valve cylinder 4| is positioned in the valve casing 28 and is adapted to be turned from one position to another by a suitable manually operable handle (not shown). The valve cylinder 4| hasa pair of passages 42 and 43, each adapted to connect any pair of the ports which are spaced 90apart.

The container It may be a high pressure cylinder provided with'a device 4! for releasing the gaseous pressure medium, in response to pulling a cable 48, and a conduit 41 for conducting the medium to the control head 40. In practice compressed air'is' stored in the container at apressure between aboutl300 and 2000 pounds per square inch and, preferably, atfl1800 pounds per square inch, at 70 F. a

The hydraulic system M for operating the piston I! under normal conditions and the source of high pressure gaseous medium are operatively connected tothe cylinder II by the control head aaesnoo The control head comprises a tubular body or casing having a cylindrical bore 5| extending from end to 'end, a slidable valve member I2 positioned in the bore, and a relief valve 54. One end of the bore has a port 0' connected by a pipe or tube 56 to the control valve 2'9 and the other end of the bore has a port 51 connected to the direction valve 21 by the pipe or tube 31. Adjacent the port 55, a port 50 is provided having the gaseous pressure medium conducting tube 41 connected thereto and which, by means of the bore BI, is in communication with the port 55. Intermediate the ports II and 59, a port is provided which has the relief valve 54 operatively connected thereto. At the other end of the control head casing and adjacent the port 51, there is provided a port I connected by a pipe or tube 62 to a port 63 at one end of the cylinder, and intermediate the ports I9 andil a port 64 is provided which is connected by a pipe to a discharge port 88 located outboard of the fuselage of the plane.

In the apparatus illustrated herein, the control head 40 is designed to permit high pressure on or other hydraulic medium to enter the port 62 of the cylinder and move the piston toward the right .to effect, for example, closing of a bomb bay door. Under normal conditions of operation,

that is, when the door is opened by oil or hy 5 head is adapted to-close the return line 3'! and to direct the oil in back of the cylinder to to the outboard discharge port 06. v

In order to accomplish the foregoing, the valve member 52 cooperates with valve seats posio tioned in the control head and is maintained in one operating position by resilient means and is moved into another operating position in response' to the gaseous pressure medium released from the container it during emergency operation.

For this purpose the valve member 52 is provided with a piston or plunger portion 10 at one end which fits snugly for sliding movement in the bore and is normally adjacent the gaseous pressure medium inlet port I! to enable the gaseous pressure medium to move the valve member 52 towards the left. A shank portion ll, of reduced diameter, is secured to the piston portion 10 which may be provided with fins I2 to slidably guide it in the bore of the control head. The other end of the shank portion ll carries a valve plug which may be in the form of a spherical portion or ball 13, which is positioned in a portion 14, of the bore ii. The portion 14 is of slightly greater diameter than the bore I and is located intermediate the ports 51 and 04.

To the right of the ball 13, the bore of the control head is provided with a valve seat 15 upon which the ball is adapted to seat and shutadapted to be engaged by the "left side Of the ball.

12 to shut of! communication between the port 1 l1 and the bore portion 14. A cylindrical hel- 40 and the valve 39, which willnow be in detail.

ical spring 40 engagesthe ball 13 and normally urges it against the valve seat Ii and a second but relatively weak spring ll engages the piston tween the valve 39 portion 19 at the other end of valve member 59. The spring 99, preferably, is positioned in an annular space provided between the bore portion 14 and the tubular member 16, while the spring 8| may be retained under adjustable compression by a perforated plug 84 threaded into the bore of the control head at 85.

The relief valve 54, which preferably is part of the control head, may be of the pop valve type. This relief valve, as illustrated herein, comprises a casing 99 having one end threaded into a socket adjacent the port 99, a valve seat 9I in the casing, and a valve member 92 urged against the seat 9I by a spring 94. The spring 94 is retained and is adapted to be adjustably tensioned by a plug 95 screwed into the lower end of the relief valve casing. If desired, the valve member 92 may have a depending stem 99 which extends through and is guided by an aperture 91. In the event the pressure of the gaseous medium passing through the bore becomes excessive, the valve member 92 is moved away from the seat 9| in opposition to the spring 94 and the pressure of the gaseous medium es capes through suitable apertures 98 in the easing 99. v

The valve 39 cooperates with the control head 49 to cut off the supply of oil or other hydraulic pressure medium to the right side of the cylinder in response to the release of the gaseous medium and admits the gaseous medium to the cylinder to move the piston toward the left. To accomplish this, the valve '39, generally known as a shuttle type valve, may comprise a casing I99 having a longitudinal bore I9I, an air inlet port I92, at one end of the bore connected to the tube 56, and an oil inlet port I94 at the other end of the bore connected to the pipe 35. Ad jacent the port I92, a valve seat I95 is provided and a similar valve seat I96 is provided adjacent the port I94.- A slidable valve member or shuttle I91 is positioned in the bore I9I which has a valve seat engaging portion I99 at each end, adapted to close the ports I92 and I94. The valve member I91 is frictionally held against shifting accidentally by a spring pressed ball member 9 adapted to seat in circumferential grooves II I in the valve member I91. The valve casing I99 is further provided with conduits 2 leading from the bore IN to an outlet port II4 which is operatively connected with an inlet port 5 at the right hand end of the actuating cylinder I5.

The valve 39 preferably is mounted on the cylinder I5 by providing the casing with a nipple H9 at the outlet port II4 which is threaded into the inlet port II5 of the cylinder, whereby a short connection between the valve III! and the cylinder is provided. It will be understood that,

if desired, the valve could be designed as part of the control head, whereby the connection beand the control head 49 is eliminated. I

In order to prevent gaseous pressure medium vfrom being trapped in the pipe 41 connecting the container I9 and the control head 49 after release of the medium, suitable venting means cooperating with the gas release actuating cable 49 are provided. These venting means also serve to vent the gaseous medium to the atmosphere in the event the gaseous medium is released accidentally due to excessive pressures developed in the container, whereby the gaseous medium will not operate the valve 39, control head 49 'having a downwardly facing valve seat and the piston I9 in the cylinder I9. Such ven't- 7i ing means preferably comprise a vent valve I29 which normally is open and is closed only while The vent valve I29 comprises a casing having an inlet port I2I connected by a pipe or tube I22 to a T-fitting I24 in the pipe 91, and having an outlet port I25 connected by a pipe or tube I29 to an outboard discharge port 99. Intermediate the inlet port I2I and the outlet port I25, the valve casing is provided. with a bore I21 I29 adapted to be engaged by a valve member I39 to shut 01? communication between the inlet and outlet ports. The valve member I39 is provided with a stem I3I extending through the upper end of the valve casing and is adapted to be engaged by the cam surface I32 of a lever I34 pivotally mounted on a bracket I35 attached to the valve casing. The cam surface is designed so that it is effective to move the valve stem downwardly and to maintain it in its downward position when lever I34 is held in its normal position by a spring member I36 having one end attached to the upper end of the lever. The lever is operatively associated with the gas release actuating means by a cable I91 attached to the cable 49, whereby when the cable 46 is pulled to effect release of the gaseous medium, the cable I31 moves the lever into a position in which the cam surface I32 permits the stem I3I to move upwardly. Upward movement of the stem and the valve member thereon is effected by a spring I39, positioned in the bore I21 to engage the valve member andmaintained in a position to urge the valve member upwardly by an adjustable spring tensioning plug I49 threaded into the bore. During release of the gaseous medium the spring I39 holds the valve member I39 against the seat I29 to prevent'the escape of gas through the vent or discharge port 96'.

While the hydraulic and pneumatic systems are illustrated and described, by way of example, in connection with a single door actuating cylinder, it will be understood that any desired number of actuating or working cylinders may be operated by the source of hydraulic pressure medium'and the gaseous pressure medium.

The. emergency gas release cable 46 may be utilized for efiecting the release of springs or other suitable devices for holding the bombs in the bomb racks. This may be accomplished by attaching to the cable 45 a cable I45 which actuates the bomb release devices simultaneously with the operation of the gas releasing de-' utilized for moving the piston I9 to efiect opening or closing of the door or the like. When it is desired to open the door the valve member 4| of the valve is placed in' the position shown in Figure 2 in solid lines so that hydraulic medium under. pressure flows from the accumulator 29 through the pipe 34 to the valve 21 and through the valve passage 42 to the pipe 35 through which it is conducted to the valve 99. The pressure of the hydraulic medium, oil for example. will force the shuttle member I01 towards the left, if the member I01 is not already in that position, as

indicated in full lines, whereby the port I02 will be closed and the port I04 will be opened and hydraulic medium enters the cylinder through the inlet II5 to move the piston I0 towards the left.

During normal operation of the apparatus, the valve member 52 of the control head 40 is urged towards the right by the spring so so that the indicated in broken lines so that oil flows from the accumulator through the valve passage 43, the pipe 31, the control head by way of ports 51 and 6|, the pipe 52, and into the cylinder to move the piston I9 towards the right. The oil in back of the piston will flow from the cylinder through the port I I5, the valve 39 by way of ports H2 and I04, the pipe 35, the valve passage 42, and the pipe 36 to the reservoir 2|.

In operation during an emergency, the cable 40 is pulled toward the right to operate the gas releasing means 45 and at the same time to move the lever I 34 in a position toenable the spring I39 to close the valve I20. .The. gas, preferably air at 1800 pounds per square inch, released from the container I5 travels through the pipe 41, the control head ports 59 and 55, and the pipe 56 to the valve 39 and is efiective to move the shuttle member I01 towards the right. The member I01 when in this position closes the oil inlet port I04 and opens the air inlet port I02 so that air flows through the valve 39 and into the cylinder to move the piston I8 towards the left to effect open ing of the door.

In the event, that the pressure of the air is more than a predetermined magnitude the valve member 92 of the valve 54 will be moved downwardly in opposition to the spring 04 and excessive pressure will be relieved. The vent valve 54 also may operate due to excessive pressure in the event the right hand end of the cylinder is partly filled with oil due to a partial stroke of the piston by hydraulic operation prior to emergency operation.

v The air entering the control head 40, also is efiective to move the valve member 52 towards the left in opposition t the spring 0|, whereby the ball 10 fits against the seat 11 to close the oil port 51 and the'ball 10 moves away from the seat 15 to' open the port '04. This enables oil in back of piston to be discharged to the atmosphere by establish communication between the ports I2I and I25. Any air trapped in the system can now flow by way of the pipe 41, the T fitting I24 and the pipe I22 to the port I2I, through the valve I20 and to the outboard discharging opening by way of pipe I25. The pressure of the air is adapted to rupture the indicator at 60', serving to indicatethat the container has been discharged and requires replacement or recharging. The apparatus is now adapted to be operated bydraulically. 7

In the event that the air is released accidentally without operation of the pull cable 45 .and the valve I20, the air will simply vent to the outboard and pressure, sufllcient to operate the control head 40 and the valve 38, will not be built up in the line 41 leading to the'control head.

From the foregoing description, it will be seen that the present invention provides a practical method and apparatus for efiecting normal and emergency operation of doors or the like. The apparatus is so controlled that it can operate hydraulically or pneumatically. In an emergency, the air or other fluid high pressure medium is utilized to convert the apparatus from low pressure operation to high pressure operation in a rapid and foolproof manner. Suitable quick acting valve devices prevent oil from getting into the air system or air getting into the oil system During high pressure operation the low pressure medium in back of the piston is discharged to lessen the resistance to movement of the piston and thereby speed up operation. Theapparatus is protected from excessive pressures and will not operate should the air be released accidentally. After emergency operation the apparatus is again ready for hydraulic operation. The high pressure medium is vented after emergency operation and will not interfere with the hydraulic operation of the apparatus. The apparatus may be readily installed, tested, inspected and recharged. The, parts of the apparatus are rugged in construction and can readily withstand the rough usage to which they may be subjected.

While the invention has been described in connection with using a high pressure fluid medium, such as gas, for effecting rapid operation of the piston I9 in an emergency, it may be desirable to use gas having a lower pressure than the hydraulic medium; This may be accomplished by increasing the eifective area of the piston portion 10 of the control head member 52 and the bore 5I of the control head so that the pressure :the pressure "of the gas utilized, the gaseous flowing from the cylinder through the pipe 82, the

control head ports GI and 54, the pipe 05, and the discharge outlet which preferably is outboard of the fuselage. The pressure of the oil discharged will rupture the indicator at the outlet 00, whereupon landing, a ground crew will readily see that the. emergency system has operated.

After the air has moved the-piston into door operating position, the cable 48 is released and the return spring I00 movesthe lever I04 into a position whereby the cam I02 moves the valve stem I0l downwardly'and causes the .valve member I00 to move away from the valve seat I20 to medium facilitates emergency operation of the piston I9 in the event that the hydraulic system fails to function.

While my invention resides in certain principles of construction and operation which have been illustrated and described in connection with the accompanying drawings, it will be apparent to those skilled in the art that the invention may be embodied in other forms of construction without departing in any manner from the spirit and scope of the invention, and I therefore do not wish. to be strictly limited to the disclosure, but rather to the scope of the appended claims.

I claim:

1. In apparatus of the class described, the" combination of a cylinder, a, fluid pressure operated piston in said cylinder, a valve operatlvely con nected to one end of said cylinder for normally permitting the passage of aliquid pressure medium into said cylinder and adapted to shutoff the liquid medium and permit the passage of a high pressure gaseous medium into said cylinder, and a second valve having a valve member therein normally positioned to permit the passage of the liquid pressure medium from the other end of the cylinder to a reservoir, said second valve being operable by the gaseous'mediumto move said valve member into a position to prevent the passage of liquid medium to the reservoir and to release the liquid medium in the other end of said cylinder. I

2. In apparatus of the class described, the combination of a, cylinder, 4;, fluid pressure operated piston in said cylinder, a valve operatively connected to one end of said cylinder for normally permitting the passage of a liquid pressure me-.

dium into said cylinder and adapted to shut off the liquid medium and permit the passage of a high pressure gaseous medium into said cylinder, and a second valve having a valve member therein normally positioned to permit the passage of the liquid pressure medium from the other end of the cylinder to a reservoir, said second valve being operable by the gaseous medium to move said valve member into a position to prevent the passage of liquid medium to the reservoir and ervoir, means for introducing into said cylinder ing the medium from said cylinder to a reservoir, means for introducing a high pressure gaseous medium into said cylinder at one end thereof, valve means operable by the gaseous medium for rendering said liquid medium introducing and conducting means ineffective at both ends of said cylinder while the gaseous medium is introduced,

and valvemeans operable by the gaseous medium for eflecting discharge of the liquid medium in the other end of said cylinder.

5. In apparatus of the class described, the combination of a cylinder, a fluid pressure operated piston in said cylinder, a source of fluid pressure medium, a reservoir, means at both ends of said cylinder for alternately supplying said medium to said cylinder and conducting said medium from said cylinder to said reservoir, valve means oper atively connected in said means at both ends of said cylinder and being normally positioned for permitting the passage of said medium to said cylinder from said sourceand from said cylinder to said reservoir, means for supplying to one end of saidcylinder a second fluid pressure medium having a much greater pressure than said first medium, said second medium being eflective tooperate. said valve means to shut of! communication between both ends of said cylinders and said first means, and means for etlecting the release or said first medium in back of the piston while said second medium is supplied in front of the piston.

6. In apparatus of the class described, the combination of a, cylinder, at fluid pressure operated at one endithereof a second fluid pressure medium having a, much greater pressure than said first medium, means operable by said second medium for rendering said first medium introducing and conducting means ineffective at both ends of said cylinder while said second medium introducing means are effective, andmeans tor eilecting discharge or said first medium in the other end or said cylinder while said second medium is introduced.

4. In apparatus of the class described the combination of a cylinder, a fluid pressure operated piston in said cylinder, means at both ends o! said cylinder for alternately introducing a liquid pressure medium into said cylinder and conductpiston in said cylinder, 9. source of pressure medium, a reservoir, a valve for normally admitting said medium to one end of said cylinder and permitting passage of said medium irom said cylinder to said reservoir, a valve for normally admitting said medium. to the other end of said cylinder and permitting passage of said medium from said cylinder to said reservoir, means for alternately connecting each. or said valveswith said'source and said reservoir respectively, means for introducing an emergency pressure medium at one end of said cylinder, said lastmans being operatively connected to both ofsaid valves to cause said emergency medium'to operate both 0! said .valves to prevent the passage 0! said first medium to and from either end of said cylinder while said emergency medium is'being introduced, and valve means associated and operable with one or said valves for eflecting the release "of said first medium in back of said piston when said emergency medium is being introduced in iron 01 said piston.

- murmur-mole. 

